Locking devices for fluorescent lamps



Sept. 9, 1969 L. DETCH 3,466,594

LOCKING DEVICES FOR FLUORESCENT LAMPS Filed Feb. 21, 1968 2 Sheets-Sheet 1 INVENTOR. MM W W L. DETCH LOCKING DEVICES FOR FLUORESCENT LAMPS Sept. 9, 1969 2 Sheets-Sheet 2 Filed Feb. 21 1968 INVENTOR. Jaw, dazzg/ BY United States Patent 3,466,594 LOCKING DEVICES FOR FLUORESCENT LAMPS Lewis Detch, 2133 Chalfant St., Pittsburgh, Pa. 15221 Filed Feb. 21, 1968, Ser. No. 707,128 Int. 'Cl. H011 33/10, 13/54 US. Cl. 339-54 12 Claims ABSTRACT OF THE DISCLOSURE means olfstanding from its face adjacent to said lamp a holder and cooperating with the usual slot of the holder which admits the bi-pins during assembly of the lamp with the holder, such lug means serving to prevent rotation of the lamp, axially, and its disengagement from the holder.

The invention comprises a locking device for fluorescent lamps, including a wafer-like locking member formed, preferably, of a dielectric or insulating material such as Nylon or substantially similar or equivalent synthetic plastic material for insertion between the lamp holder and the end of a lamp with a relatively snug, contacting fit between such parts, said locking member being provided with open-ended slots for reception of the bi-pins of the lamp, such slots being of a width preferably of slightly less lateral dimension than the diameter of the bi-pins and terminating substantially centrally of the said locking member in circular apertures of a diameter slightly greater than the diameter of the bi-pins so that the locking member will be capable of engagement with said bi-pins with a snap action and thus be held in assembled relation relative to the lamp end and the lamp holder, the locking member being provided at its face adjacent to the lamp holder with offstanding lug means for engagement in the usual slot of the lamp holder through which the bi-pins are inserted during assembly of the lamp with the lamp holder, and serving to prevent axial rotation of the lamp with respect to the lamp holder and thus insure maintenance of the lamp with its bi-pins in proper electrical contact with the usual spring contact elements, or socalled finger clips, of the lamp holder to thus forestall disengagement of the lamp from the lamp holder due to vibration or shock and prevent it from falling, all as will be explained hereinafter more particularly and finally claimed.

In the accompanying drawings illustrating the invention, in the several figures of which like parts are similarly designated,

FIG. 1 is a schematic fragmentary perspective view of an assembly of a fluorescent lamp with a pair of complemental lamp holders, a locking device according to the invention being shown inserted between the end of the lamp and the lamp holder at the right-hand end of the figure, and a locking device being shown at the left-hand end of the figure in position for insertion at that end,

FIG. 2 is an elevational view of the lamp holder adjacent face of a preferred form of the locking device of the invention,

FIG. 3 is an edge elevational view of the locking device shown in FIG. 2 as viewed from the right-hand side of FIG. 2,

Patented Sept. 9, 1969 ICC FIG. 4 is a view similar to that of FIG. 2, but showing the opposite face of the device,

FIGS. 5, 6 and 7 are views similar to FIGS. 2, 3 and 4, but illustrating a modification of the locking device,

FIGS. 8, 9 and 10 are views similar to FIG. 2, but showing modifications of the locking device in which means are provided for enhancing the pliability of those portions adjacent to the bi-pin receiving slots,

FIGS. 11 and 12 show, in perspective, the opposite faces of a further modification of the locking device,

FIG. 13 shows, in perspective, a still further modified form of the locking device in which means are provided for attachment of handle means whereby the locking device may be inserted in and removed from an overhead installation of the lamp and its holders,

FIG. 14 is a fragmentary sectional elevation showing the locking device of FIG. 13,

FIG. 15 is a perspective view of means whereby any of the locking devices of FIGS. 1 to 12, and 18, may be provided with handle means to facilitate overhead installation.

FIG. 16 is a fragmentary sectional elevation, taken in the plane of the axis of the securing bolt or screw, of the parts shown in FIG. 15,

FIG. 17 shows in perspective another modification of the locking device in which the holder engaging lug is so formed as to afford an added frictional engagement with the bi-pin admitting slot of the lamp holder, and especially designed for relatively large sizes of the locking means, and

FIG. 18 is a perspective view showing another form of the holder engaging lug of the locking member particularly adapted for use with locking members of relatively large sizes.

The primary object of the invention is to provide locking means for the lamps of fluorescent lamp installations, particularly in locations subject to vibration and shock which might cause the lamps to become disengaged from their holders, such, especially, as in overhead installations where the lamps might fall and break, or might injure persons working or passing below them.

Another object is to provide a fluorescent lamp locking device which may be operatively assembled between the end of the lamp and the adjacent face of the lamp holder simply by insertion between these cooperating parts and Without the use of tools or special manipulation to lock it in place.

A further object is to provide a fluorescent lamp locking device which may be inserted into, and removed from, lamp-locking disposition between the lamp and its holder by a simple straight line sliding manipulation and which, when in operative locking position will not only lock the lamp against escape from the lamp holder but will serve to reinforce the bi-pins of the lamp and assure a good alignment between the fingers clips of the holder and such bi-pins to that provide effective electrical circuitry through the lamp.

Various types of fluorescent lamp locks have hereto fore been provided, such as those covered by the nowexpired patents of Bixby, Nos. 2,336,587 and 2,336,588, of Dec. 14, 1943, and 2,401,408, of June 4, 1945.

The devices of all of these patents are made of fiberboard and have the fault that they are subject to swelling and shrinkage and hence to distortion and failure particularly when subjected to moisture or high humidity. Also, they are not capable of easy application and removal, especially when distorted.

The present device being made from a synthetic material, preferably nylon, which is not appreciably subject to temperature changes, is moisture repellent, is an excellent insulator, is odorless, may be molded to exact measurements and specifications, has a coeflicient of expansion similar to that of the glass from which the fluorescent tubes are made, and is fire resistant, it is admirably suited to the function for which the device is designed.

Also, the lamp lock of the invention, made of a selected plastic material having the characteristics just above described, is of unitary form without moving parts, will not corrode or adhere to the lamps, bi-pins or sockets, is not affected by dirt, grit or other extraneous matter, or by corrosive fumes or weathering. It is also of long life with failure-free service, and due to the simplicity of its design and mode of installation it may be installed, adjusted and removed by relatively unskilled mechanics. Furthermore, due to the inherent lubricity and flexibility of the plastic material of which it is made the lock is easily inserted into locking position in positive locking engagement with the bi-pins of the lamp, and is capable of ready detachment from locking position, without injury to the said bi-pins inasmuch as the slots leading to the locking apertures will readily slide over the bi-pins during insertion and disengagement of the lock.

Lamp locks of metal, such as flat or coiled springs, have been provided, but these often lead to failure in that they may cause cracking of the lamps due to variations in temperature conditions. Moreover, they present electrical hazards, exposing personnel to shocks due to short circuits between the lamps and holders. The lamp lock of the present invention has none of these faults.

As shown in the drawings, the locking device of the invention may take a variety of forms, sizes and thicknesses appropriate to the types and sizes of lamps and lamp holders with which it is designed to be associated.

In its simplest form, as shown in FIGS. 1 to 4, the lamp lock comprises a flat, relatively thin, wafer-like body 1 with a depending grip member 2 preferably perforated at 3 for the reception of adjusting means such as those shown in FIGS. and 16 later to be described. Extending inwardly of the body 1 from its upper edge is a pair of open-ended slots 4 terminating substantially midway of the body in aperture 5 for the reception of the bi-pins of the lamp, not shown but which are of conventional form as are the lamp 6 and lamp holders 7, FIG. 1. The slots 4 are of slightly less width than the diameter of the said bi-pins, and the apertures 5 are of slightly greater diameter than the diameter of such pins, say .002 to .005 of an inch greater. Thus, when the lock is inserted between the end of the lamp and the adjacent face of the lamp holder, with the slots 4 in register with the bi-pins of the lamp, contacting sliding of the walls of the slots along the bi-pins will finally register the said bi-pin-s in the apertures 5 and they cannot escape therefrom due to the confining character of the slots where they join the apertures.

On its face which contacts the face of the lamp holder, as indicated at the left of FIG. 1, the body of the lock carries an integral offstanding lug 8 for engagement in the slit of the lamp holder through which the bi-pins of the lamp are introduced. Thus, strain on the bi-pins, and on the finger clips therefor, to withstand possible axial rotation of the lamp relative to the lamp holder, such as often occurs due to shock or vibration, will be avoided and will be transferred to, and prevented by, the lug 8 and its engagement in the lamp holder slot.

As indicated by the hatching in FIGS. 2 and 4, the faces of the body 1 of the lock member may be knurled, or otherwise roughened or interrupted, for the double purpose of affording its better frictional engagement with the adjacent faces of the lamp holder and lamp end cap to prevent possible axial rotation of the lamp, to reinforce the parts, and to provide passageways between such parts for ventilation to reduce likelihood of overheating. Also such roughening will serve to close out dust and dirt and provide insulation against arcing within the lamp holder.

As shown in FIGS. 5 to 7, the lock is provided on its face which contacts the end of the lamp with a support member 9 is disposed that when the lock is fully inserted, with its apertures 5 in register with the bi-pins of the lamp,

it will be in contact with, or close proximity to, the periphery of the lamp and will, due to the frictional engagement of the lock with the face of the lamp holder and its confinement between such face and the end of the lamp, serve in a measure to support the lamp. It will also, by engagement with the periphery of the lamp, serve to limit over-insertion of the lock and its possible distortion or other injury.

Due to the nature of the material of which the lock is made it has inherent resiliency and thus will, when it is engaged with the bi-pins of the lamp in entering position with its slots 4, enable the outer arms 10 of the lock to spring outwardly sufficiently to permit passage of the bi-pins through the slots and into the apertures 5. However, in order to enhance such resiliency the central arm 11 may be provided with a slit 12 terminating in an aperture 13 provided with laterally extending slots 14 (FIG. 8), or the outer arms 10 may be similarly slitted, either vertically (FIG. 9), or laterally (FIG. 10), but without the slots 14 at the aperture 13. Also, as shown in FIGS. 8 to 10, the central arm 11 may extend upwardly above the termini of the outer arm 10 in order to furnish a guide for its insertion between the bi-pins of the lamp. The slitting of the arms will be found advantageous especially in the locks which are relatively thick wafers adapted primarily for heavy installations, or where, due to unusual separation of the ends of the lamp from the faces of the lamp holders due to their faulty installation, or differences in the length of the lamps, the spacing is such that the thin locks are not appropriate to provide a snug mounting.

It may be noted, here, that in normal production locks of from .020 to .066 of an inch have been found adequate for all normal fluorescent lamp installations, but these dimensions may be altered to accommodate the lock to other, or deviating, installations.

FIGS. 11 and 12 show the lamp lock of the invention having a substitute for the support member 9 shown in FIGS. 5 to 7, and this substitute is in the form of an arcuate extension 15 to lie below, and furnish a stop against, the periphery of the lamp.

In FIGS. 13 and 14 there are shown means whereby the lamp lock may be applied to and removed from fluorescent lamp installations located in overhead positions. In this form the lock is provided with a depending, integral socket member 16 interiorly screwthreaded to receive the end of a handle member 17 of a preferred, adequate length to answer all normal purposes.

In FIGS. 15 and 16 the lamp lock is provided with a detachable, axially slotted, interiorly screwthreaded socket member 18 assembled with and attached to lock, such as those shown in FIGS. 1 to 12, by a screw or bolt 19 extending transversely through the socket member 18 and through the perforation 3 in the depending grip member 2.

In FIG. 17 a relatively large, thick, heavy-duty lamp lock is shown. This lock is similar, in general, to that shown in FIG. 8 but its offstanding lug 20 provided with lateral beads 21 is made relatively springy by the provision of a slit 22 which, upon insertion of the lock between the lamp end and the lamp holder, will afford a frictional fit of the lug 20 within the slot of the lamp holder and enhance the securement of the lock in the holder and between such lamp holder and the lamp end.

It will be noted, also, that the grip member 2 of the lamp lock of FIG. 17 is provided with a socket member 23 similar in function to that FIGS. 13 to 16, but it will obvious that this could be omitted and the grip member 2 could be like those of FIGS. 1 to 12, 15 and 16.

In FIG. 18 there is shown another relatively heavy-duty lamp lock having, in general, the structural characteristics of that of FIG. 17 and also adapted for use with relatively large lamp holders. In this form the lug 24 is provided with an upwardly extending tang 25 for engagement in the slot of the lamp holder.

In all of its forms, the leading, or upper, edges of the arms of the lamp lock may be tapered to a thickness'less than that of the body in order to facilitate its insertion between the end of the lamp and the adjacent face of the lamp holder, particularly in those installations where such space is rather confined.

From the foregoing it will be seen that the lamp lock of the invention is well adapted to serve not only as a means for insuring the desired integrity of a fluorescent lamp installation by preventing axial rotation of the lamp with relation to the lamp holders, but also as a means for providing a vibration and shock deterrent by virtue of the desired relatively tight fit of the several elements, lamp, lamp holder and lock, to forestall axial as well as rotative movement of the lamp, thereby insuring a stable installation free of short circuits and injury to or deformation of the relatively delicate members such as the bi-pins of the lamp and the finger clips of the lamp holders.

Quite obviously, in a fluorescent lamp installation the lamp locks of the invention will be inserted between both ends of the lamp and the adjacent faces of the two lamp holders.

It should be noted, moreover, that in the case of those locks in which the arms are provided with slits to facilitate insertion with respect to the bi-pins, such as shown in FIGS. 8 to 12, 17 and 18, the necessary lateral distortion of the bi-pin engaging slots as they engage the bi-pins occurs instantly because the arms are in a neutral or relaxed state and thus, as the lock is pushed in to its operative position with the bi-pins positioned in the complemental apertures at the inner ends of the slots the distortion of the slots will be absorbed in the slitted portions of the arms, and when the bi-pins are finally home in their complemental apertures the arms will resume their normal rclaxed state and block release from the bi-pins. This is effective particularly in respect to lamp locks of a relatively thick nature.

In the lamp locks of the types shown in FIGS. 1 to 7, 13 and 15, which can be relatively thin, and wherein no relief slits are employed, the inherent resiliency of the locks, and the lubricity of the material of which they are made, will sufiice to permit their easy insertion into operative position in register with the bi-pins of the lamp.

It will be noted that the presence of the oifstanding lug in the slot of the lamp holder will, due to its size and coolness, serve to choke off and confine any arcing in the lamp holder, and thus reduce the chance of fire to a minimum, or completely eliminate it.

Also, the one-piece, light weight nature of the lamp lock makes it particularly attractive and practical because it will, when in operative position, exert no gravitational strain upon the relatively fragile and delicate bi-pins. In this connection it will be noted that the lamp lock has a weight of less than one ounce.

It will be appreciated that the resiliency of the arms of the lock can be varied to accommodate it to many types of lamps and lamp installations by varying the number, arrangement and size of the slits in such arms and in the body of the lock.

As above indicated, the lamp lock when installed in operative position with the bi-pins of the lamp in register with the apertures at the inner ends of the slots it assumes, and will retain, a relaxed state, and it serves to provide a lamp holding effect with relatively little mechanical stress at the bi-pins of the lamp and at the lamp holder. However, in the presence of vibration or shock, when the need for maintaining effective engagement of the bi-pins of the lamp with the finger clips of the lamp holder becomes more imperative, the locking effect of the lock is enhanced and it holds gradually tighter and tighter. As vibration decreases the lock again holds less tightly and it returns to normal or relaxed condition while at the same time holding the lamp against axial rotation and possible disengagement from the lamp holders and insuring proper electrical contact of the bi-pins of the lamp with the finger clips of the lamp holders. The mechanical stress is not confined to any one area of the lamp and lamp holders but is distributed over the entire holding area of the lock. In this respect the lower half of the lock absorbs a substantial portion of the mechanical stress due to its cushioning of the lamp holder, and the offstanding lug disposed within the slot of the lamp holder also absorbs an appreciable part of the stress. The upper half of the lock with its roughener surface, when used, and grip member, and the fact that the material of which the lock is made, nylon or similar plastic for example, is relatively elastic, make possible further absorption of the mechanical stress. The lock is not a rigid clamp which concentrates its fastening ability in any single area.

Thus, the holding action of the lock although quite positive is still gentle and relatively flexible, permitting minor axial movement of the lamp just sufficient to meet requirements while still maintaining it in proper operating position with good electrical contact.

The lock serves admirably to eliminate lamp lock failure, particularly as compared with paper and fiber locks in that, unlike such locks, it never sets, is always in a relaxed state, is not subject to weathering and deterioration due to atmospheric conditions and may be repeatedly installed and removed without losing its effectiveness.

Lamps often become inoperative in their lamp holders because of dirty, oxidized bi-pins, and the lamp lock of the invention can be used to clean and brighten the bi-pins by simply drawing it over the bi-pins a few times, thus insuring better electrical contact and lamp operation.

Various changes and modifications are considered to be within the principle of the invention.

What I claim is:

1. A lamp lock for assembly of a fluorescent lamp and the lamp holder therefor, comprising a wafer-like locking member for insertion between the end of the lamp and the adjacent face of the lamp holder, said locking member being provided with open-ended slots for passage therethrough of the bi-pins of the lamp, said slots terminating inwardly of the locking member in apertures for the reception of said bi-pins, and a lug otfstanding from the face of the locking member adjacent to the face of said lamp holder and engageable in the slot of said lamp holder through which the bi-pins of the lamp are entered during installation of the lamp, the engagement of said apertures with the bi-pins of the lamp, and of said lug with the slot of said lamp holder serving to prevent relative rotation of said lamp and lamp holder and possible separation of the lamp from the lamp holder.

2. A lamp lock as defined in claim 1, in which its said slots are of a width slightly less than the diameter of said bi-pins and the diameter of its said apertures is slightly greater than the diameter of the bi-pins.

3. A lamp lock as defined in claim 1, in which the said bi-pin receiving slots divide the body of the locking member into at least three upstanding arms, and certain of said arms are provided with slit means serving to accommodate a modicum of deformation thereof to accommodate the bi-pins during their passage through said slots.

4. A lamp lock as defined in claim 1, in which the face of said locking member adjacent to said lamp end is provided with an offstanding support member so disposed as to closely underlie the periphery of the lamp.

5. A lamp look as defined in claim 1, in which the faces of the locking member are roughened for retaining engagement with the adjacent faces of the lamp end and lamp holder.

6. A lamp look as defined in claim 1, the same being formed from a plastic material substantially stable in the presence of atmospheric changes.

7. A lamp lock as defined in claim 6, in which the plastic material is a synthetic material such as nylon.

8. A lamp lock as defined in claim 1, in which said lug is of a transverse dimension slightly greater than the transverse dimension of the slot of said lamp holder and is slitted substantially normal to the adjacent face of said lock member to afford it a resiliency sufficient to enable it to be entered into the slot of said lamp holder.

9. A lamp lock as defined in claim 8, in which the outer side edges of said lug are provided with laterally olfstanding beads for bearing against the sides of the slot of the lamp holder in frictional engagement therewith.

10. A lamp lock as defined in claim 1, in which the locking member is provided with means for attachment thereto of a handle member whereby the locking member may be manipulated for installation and removal in relation to overhead lamp installlations.

11. A lamp lock as defined in claim 10, in which the said attachment means comprise a socket member, and said socket member is secured to a grip member depending from said locking member.

References Cited UNITED STATES PATENTS 8/1941 Bryant et al. 339 -54 6/1946 Bixby 33954 MARVIN A. CHAMPION, Primary Examiner I. H. MCGLYNN, Assistant Examiner US. Cl. X.R. 339-75 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,466,594 September 9, 1969 Lewis Detch It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 56, "that" should read thus Column 3, line 39, "aperture" should read apertures line 74, "is", first occurrence, should read so Column 4, line 22, "arm" should'read arms line 67, before "Figs." insert of Signed and sealed this lst day of September 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer 

